Methods for cross component dependency reduction
AssigneesBeijing Bytedance Network Technology Co., Ltd., Bytedance Inc.
InventorsZhipin Deng, Li Zhang, Hongbin Liu, Kai Zhang, Jizheng Xu
Life of this patent
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Abstract
A method for visual media processing, including: computing, during a conversion between a current video block of visual media data and a bitstream representation of the current video block, a cross-component linear model (CCLM) and/or a chroma residual scaling (CRS) factor for the current video block based, at least in part, on neighboring samples of a corresponding luma block which covers a top-left sample of a collocated luma block associated with the current video block, wherein one or more characteristics of the current video block are used for identifying the corresponding luma block.
Claims20
A method of processing video data, comprising:
- determining, during a conversion between a current chroma video block of a video and a bitstream of the video, that a scaling process is applied on chroma residual samples of the current chroma video block;
- and
- performing the conversion by applying the scaling process on the chroma residual samples,
- wherein, in the scaling process, the chroma residual samples are scaled based on at least one scaling factor before being used to reconstruct the current chroma video block,
- wherein the at least one scaling factor is derived based on an averaged luma variable computed based on at least one neighboring luma block of a video unit of the video which is determined based on a luma sample corresponding to a top-left sample of the current chroma video block, and
- wherein, in response to all of the at least one neighboring luma block being unavailable, the averaged luma variable is set to a default fixed value.
An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:
- determine, during a conversion between a current chroma video block of a video and a bitstream of the video, that a scaling process is applied on chroma residual samples of the current chroma video block;
- and
- perform the conversion by applying the scaling process on the chroma residual samples,
- wherein, in the scaling process, the chroma residual samples are scaled based on at least one scaling factor before being used to reconstruct the current chroma video block,
- wherein the at least one scaling factor is derived based on an averaged luma variable computed based on at least one neighboring luma block of a video unit of the video which is determined based on a luma sample corresponding to a top-left sample of the current chroma video block, and
- wherein, in response to all of the at least one neighboring luma block being unavailable, the averaged luma variable is set to a default fixed value.
A non-transitory computer-readable storage medium storing instructions that cause a processor to:
- determine, during a conversion between a current chroma video block of a video and a bitstream of the video, that a scaling process is applied on chroma residual samples of the current chroma video block;
- and
- perform the conversion by applying the scaling process on the chroma residual samples,
- wherein, in the scaling process, the chroma residual samples are scaled based on at least one scaling factor before being used to reconstruct the current chroma video block,
- wherein the at least one scaling factor is derived based on an averaged luma variable computed based on at least one neighboring luma block of a video unit of the video which is determined based on a luma sample corresponding to a top-left sample of the current chroma video block, and
- wherein, in response to all of the at least one neighboring luma block being unavailable, the averaged luma variable is set to a default fixed value.
A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises:
- determining that a scaling process is applied on chroma residual samples of the current chroma video block;
- and
- generating the bitstream by applying the scaling process on the chroma residual samples,
- wherein, in the scaling process, the chroma residual samples are scaled based on at least one scaling factor before being used to reconstruct the current chroma video block,
- wherein the at least one scaling factor is derived based on an averaged luma variable computed based on at least one neighboring luma block of a video unit of the video which is determined based on a luma sample corresponding to a top-left sample of the current chroma video block, and
- wherein, in response to all of the at least one neighboring luma block being unavailable, the averaged luma variable is set to a default fixed value.
Dependencies are inferred from the claim text.